Aircraft wing section assembly

ABSTRACT

An aircraft wing section assembly is disclosed having a structural spine, a movement mechanism including a support rod extending through the structural spine, a first lever, for connection to and for moving a first moveable control surface, pivotally mounted to the support rod, a second similar lever for connection to and for moving a second moveable control surface, and a connection mechanism for connecting the first and second levers such that pivotal movement of the first lever causes pivotal movement of the second lever, and an actuation mechanism for actuating pivotal movement of the first lever, such that, in use, when the actuation mechanism actuates pivotal movement of the first lever, the second lever also pivotally moves, thus causing movement of both the first and second moveable control surfaces. Also disclosed is an aircraft wing assembly, an aircraft and a method of operating an aircraft.

BACKGROUND OF THE INVENTION

The present disclosure relates to an aircraft wing section assembly.

The present invention concerns aircraft wing section assemblies. Moreparticularly, but not exclusively, this invention concerns an aircraftwing section assembly comprising a structural spine extending in aspanwise direction of the wing section.

The invention also concerns an aircraft wing assembly, an aircraft and amethod of operating an aircraft.

Aircraft are provided with ailerons to control roll movement of theaircraft. These are typically located on the trailing edges of thewings, and often at a location towards the tip of the wings. Forexample, on a port wing, a trailing edge aileron may be controlled topivot downwards in relation to the rest of the wing to provideadditional lift (upwards force) to the wing and to roll the aircraftclockwise (when looking at the aircraft from the front). At the sametime, on the starboard wing, the trailing edge aileron may be controlledto pivot upwards in relation to the rest of the wing to providedownwards force to the wing and to roll the aircraft clockwise. Theailerons may also be used to alleviate gust loading on the aircraft.

However, for high aspect ratio (wing span divided by mean chord) wings(i.e. long and slender wings with an aspect ratio of 12 or more) thatare torsionally flexible or where the ailerons are located very near thetip of the wing, there can be a lot of deformation of the wing when theailerons are moved. For example, if the aileron is moved upwards, thiscould cause the rest of the wing to also flex or twist in such a waythat negates the aileron effect wishing to be achieved. In fact, aresultant negative or adverse effect may be achieved (known as aileronreversal).

Further, increasing the span of the aileron increases its slendernessand this leads to further twisting of the aileron and reduces itseffectiveness. On the other hand, if the aileron is split into multiple,shorter ailerons, this increases the complexity, cost and weight. Thismay also allow less space for the flaps of the wing.

However, high aspect ratio wings are important as they reduce induceddrag and so increase fuel burn efficiency, and so reduce operating costsand environmental impact.

In addition, in high aspect ratio wings, there is often little space inthe wing for the actuation mechanism of the ailerons. This may mean thatfairings are used to create additional volume, but this increasesprofile drag of the wing.

This issue could be addressed by using flaperons—i.e. control surfacesthat can act as both flaps and also ailerons. This gives more rollmoment, when needed. However, these flaperons are then less optimisedfor use as flaps and take up space that could be used by flaps, meaningthe wing overall is less efficient.

The present invention seeks to mitigate the above-mentioned problems.Alternatively or additionally, the present invention seeks to provide animproved aircraft wing section assembly.

SUMMARY OF THE INVENTION

The present invention provides, according to a first aspect, an aircraftwing section assembly comprising a structural spine extending in aspanwise direction of the wing section, a movement mechanism comprisinga support rod extending in a chordwise direction of the wing section,through the structural spine, from a first end to a second end, a firstlever, for connection to and for moving a first moveable controlsurface, pivotally mounted to the first end of the support rod, forpivotal movement with respect to the support rod, a second lever, forconnection to and for moving a second moveable control surface,pivotally mounted to the second end of the support rod, for pivotalmovement with respect to the support rod, and a connection mechanism forconnecting the first and second levers such that pivotal movement of thefirst lever with respect to the support rod causes pivotal movement ofthe second lever with respect to the support rod, and an actuationmechanism for actuating pivotal movement of the first lever with respectto the support rod, such that, in use, when the actuation mechanismactuates pivotal movement of the first lever with respect to the supportrod, the second lever also pivotally moves with respect to the supportrod, thus causing movement of both the first and second moveable controlsurfaces. In embodiments, the pivotal movement of the second lever withrespect to the support rod is caused by interconnection of theconnection mechanism between the first lever and the second lever.Therefore, in operation of such embodiments and when the connectionmechanism is connected to the first and second levers, pivotal movementof the first lever with respect to the support rod causes movement ofthe connection mechanism with respect to the support rod, wherein themovement of the connection mechanism causes pivotal movement of thesecond lever with respect to the support rod.

In the above and below, “extending in a spanwise/chordwise direction”means extending with at least a component in that direction. It does notrequire for the direction to be exactly parallel with the span or chordof the wing or wing section.

The aircraft wing section assembly may comprises only a small spanwisesection of an aircraft wing and may only comprise a structural portionof the section.

The structural spine may extend from a root portion to a tip portion ofthe wing section.

The first moveable control surface may be a leading or trailing edgecambering device (similar to an aileron), which is controlled to move bythe first lever. The second moveable control surface may be a leading ortrailing edge cambering device, which is controlled to move by thesecond lever. The first moveable control surface may be a trailing edgecambering device and the second moveable control surface may be aleading edge cambering device.

These cambering devices may provide roll control to the aircraft. Forexample, on a port wing, the leading and trailing edge cambering devicesmay be controlled to pivot downwards in relation to the rest of the wingto provide additional lift (upwards force) to the wing and to roll theaircraft clockwise. At the same time, on the starboard wing, the leadingand trailing edge cambering devices may be controlled to pivot upwardsin relation to the rest of the wing to provide downwards force to thewing and to roll the aircraft clockwise. A roll responsiveness of from−30 degree to +30 degrees in 7 seconds may be required. The camberingdevices may also be used to alleviate gust loading on the aircraft.

It is helpful to have both the leading and trailing edge camberingdevices on the wing.

This is especially important for high aspect ratio (long and slender)wings and/or where the aileron (at the trailing edge) is located verynear the tip of the wing. This is because, if the aileron is located along way from the wing root and/or if the wing is very flexible(torsionally), there can be a lot of deformation of the wing when theaileron is moved. For example, if the aileron is moved upwards, thiscould cause the rest of the wing to also flex or twist such that itnegates the aileron effect wishing to be achieved. In fact, a resultantnegative or adverse effect may be achieved (known as aileron reversal).

Having a leading edge cambering device as well (as a trailing edgeaileron or cambering device) balances the change in camber of the wholewing chord and so can ensure aileron reversal does not happen.Furthermore, the leading edge provides additional roll control surface.This means that the cambering devices may be shorter and take up lessspace along the span of the wing. This gives more space for flaps on thewing, for example, and allow the wing to be better optimised.

The first and second levers may be directly or indirectly pivotallymounted to the support rod.

Such an arrangement provides a compact and lightweight way of actuatingboth first and second levers at the same time. This could be used toactuate a leading and trailing edge cambering device at the same time.This is especially useful in a tip portion of a wing, and especially ofa high aspect ratio wing, where space is limited but where significantcambering device control surface is required in order to provide therequired control movement (e.g. amount of roll required) and rate ofmovement (e.g. a required roll rate for certification and pilothandling) for the aircraft.

In addition, having the first and second levers connected through thesupport rod, allows the hinge moments on the levers to counteract eachother and provide an efficient structure to deal with the loadsexperienced. This is especially helpful as the hinge moments of theleading and trailing edge cambering device surfaces will typically be inopposing directions. Hence, the support rod may take a significant partof the hinge load between the leading and trailing edge surfaces (orother moveable controls surfaces) and reduce the transverse load intothe wing structure.

The structural spine may comprise a box structure. It may have arectangular cross-sectional area. The cross-section may be between 4 mm(e.g. for a micro drone) and 4 m (e.g. for a large passenger aircraftsuch as the A380) high. The chord/width may be between 40 mm (e.g. for amicro drone) and 20 m (e.g. for a large passenger aircraft such as theA380). The height to chord ratio may be between 0.05 and 0.30.

Preferably, the structural spine comprises a monolithic box structure.

The box structure may be formed of composite material. A monolithic boxstructure is an especially efficient structure. Composite materialenables the box structure to be lightweight. Having a relatively smalland efficient box structure, enables the leading and trailing edgecambering devices to be bigger and so provide more control surface area.It also reduces manufacturing cost (due to reduced fasteners, drilling,assembly etc.).

It is desirable that the support rod extends through the structuralspine at a central (height-wise) location on the box structure. This isthe “neutral axis” of the cross-section for upwards/downwards bending.This is because this part of the box structure is less load bearing (theload mainly being taken by the top and bottom).

Preferably, the support rod comprises an elongate section extendinginternally through the structural spine between the first and secondends, wherein the first end comprises a first end stopper locatedadjacent to a first external side of the structural spine for preventingthe first end from moving in a first direction through the first side,and wherein the second end comprises a second end stopper locatedadjacent to a second, opposite external side of the structural spine forpreventing the second end from moving in a second direction, opposite tothe first direction, through the second side.

Hence, the stoppers collectively prevent the support rod from moving inrelation to the structural spine. Both tension loads and compressionloads can be passed through the rod. This enables hinge moments on thelevers to counteract each other through the support rod and provide anefficient structure to deal with the loads experienced.

The support rod may be configured to take tension and compression.Alternatively, or additionally, it may be pre-tensioned.

Preferably, the actuation mechanism comprises a cable connected to thefirst lever at a first cable connection point, the cable being connectedto a pull mechanism for pulling the cable such that the first cableconnection point moves.

Such a mechanism is lightweight and efficient for the loads required.This is because the cable only needs to take a tension force, and so islighter than a rod, that would also need to take compression.

Alternatively, the actuation mechanism may comprise a linear actuator,such as a screw actuator, the linear actuator connected to the firstlever at a first actuator connection point.

More preferably, the actuation mechanism further comprises a pulley andwherein the cable extends around the pulley.

Even more preferably, the cable is also connected to the first lever ata second cable connection point.

This provides double the moment on the first lever for the same pullforce on the cable. Hence, this further adds to the efficiency of themechanism.

Even more preferably, the second cable connection point is on anopposite side of the pulley to the first cable connection point.

Hence, when the cable is pulled, the first cable connection point movesin a first direction and the second cable connection point moves in asecond opposite direction.

Preferably, the actuation mechanism comprises a crank lever, mounted tothe first lever such that it extends transverse to the first lever andwherein the first cable connection point is located on a first end ofthe crank lever, to a first transverse side of the first lever.

More preferably, the second cable connection point is located on asecond opposite end of the crank lever, to a second, opposite transverseside of the first lever.

Preferably, the connection mechanism comprises at least one connectorextending in a chordwise direction of the wing section, through thestructural spine.

The at least one connector may be spaced from the support rod (alsoextending in a chordwise direction of the wing section, through thestructural spine) in a spanwise direction.

For example, the connector may be a rod or a cable.

More preferably, the connection mechanism comprises a second connectorextending in a chordwise direction of the wing section, through thestructural spine.

This second connector may be spaced from the support rod in a spanwisedirection, on an opposite side to the first connector.

Having two connectors allows each connector to only have to take atension force and so the first and second connectors can be cables. Thismeans the connection mechanism can be lightweight. It also enables theholes in the structural spine (needed to allow the cables to passthough) to be very small as the thickness of the cables are small.

If there is only one connector, this has to be a rod, capable of takingcompression as well as tension and so needs a bigger hole (but half thequantity of holes).

The connector(s) are preferably connected to ends of the first andsecond levers. This increases the moment between the connector(s) andthe first and second levers.

It is desirable that the connector(s) extend through the structuralspine at a central (height-wise) location on the box structure. This isbecause this part of the box structure is less load bearing (the loadmainly being taken by the top and bottom).

Preferably, the first lever is part of a first lever mechanism forconnection to the first moveable control surface, and wherein the firstlever mechanism also comprises a connecting link pivotally mounted tothe first lever at a connecting link connection point.

Similarly, the second lever is part of a second lever mechanism forconnection to the second moveable control surface, and wherein thesecond lever mechanism also comprises a second connecting link pivotallymounted to the second lever at a connecting link connection point.

More preferably, the connecting link connection point is closer to thepoint of pivotal mounting of the first lever to the support rod than thelocation of the first cable connection point.

This provides a greater moment arm for the cable, about the pivot pointof the first lever, compared to the connecting link. This means thatless cable force and movement is required to move the connecting link(and moveable control surface).

If, instead of a cable, a linear actuator is used, the connecting linkconnection point may be closer to the point of pivotal mounting of thefirst lever to the support rod than the location of the first actuatorconnection point. This means that less actuator force and movement isrequired to move the connecting link (and moveable control surface).

Preferably, the first lever mechanism further comprises a D-shaped crankpivotally connected to the structural spine and connected to theconnecting link such that movement of the connecting link causes theD-shaped crank to pivot with respect to the structural spine.

The first moveable control surface may be mounted on the D-shaped crankand so pivots with the D-shaped crank. The D-shaped crank may bedirectly or indirectly connected to the structural spine.

Similarly, the second lever mechanism further comprises a secondD-shaped crank pivotally connected to the structural spine and connectedto the second connecting link such that movement of the secondconnecting link causes the D-shaped crank to pivot with respect to thestructural spine. The second moveable control surface may be mounted onthe second D-shaped crank and so pivots with the second D-shaped crank.The second D-shaped crank may be directly or indirectly connected to thestructural spine.

Preferably, there are a plurality of movement mechanisms spaced apartalong the structural spine. This distributes the hinge moment loadacross multiple actuation connection points along the span of thecontrol surface and therefore reduces the internal structuralreinforcement required on the control surface (for example, in the formof cross/diagonal ribs) to prevent twisting. This is especiallyimportant to prevent twisting of a long and slender trailing edgeaileron/cambering device, that otherwise might occur if using twoactuator connection points positioned closely together near the inboardend of the aileron due to spacing constraints.

There may be 3, or as many as 5 or 6, movement mechanisms. The movementmechanisms may be spaced apart along the span of the structural spine.

Having a plurality of movement mechanisms minimises moveable controlsurface (cambering device) twisting and means a lighter, lessstructurally robust design is needed. This is especially important for atrailing edge moveable control surface where structural cross sectionsare typically thin. Reducing the loads on each movement mechanism canreduce the weight of the movement mechanism and associated connectionlugs on the control surface.

Each movement mechanism is controlled and moved by the same actuationmechanism. In other words, the actuation mechanism is capable of movingall first and second levers.

Preferably, the aircraft wing section assembly further comprises a firstmoveable control surface connected to the first lever and a secondmoveable control surface connected to the second lever, wherein one orboth of the moveable control surfaces comprise a flexible skin adjacentto connection of the surface to the lever.

This provides a smooth aerodynamic surface, even when the moveablesurface has been moved to an extreme position by the first or secondlever. The flexible skin may be formed of carbon fibre.

According to a second aspect of the invention there is also provided anaircraft wing assembly including the aircraft wing section assembly asdescribed above, wherein the aircraft wing section assembly is locatedat a tip portion of the aircraft wing assembly.

Preferably, the aircraft wing assembly comprises a foldable wing tipportion and wherein the aircraft wing section assembly is located in thefoldable wing tip portion, such that it is located outboard of the fold.Having a foldable wing tip portion allows the wing span to be large butstill be able to be folded to fit into the ground space available.

The pull mechanism may be located outboard of the fold.

Alternatively, the pull mechanism is located inboard of the fold, andwherein the pull mechanism includes a cable link transfer mechanism totransfer movement of a cable inboard of the fold into movement of thecable outboard of the fold.

The span of the foldable wing tip portion may be a significantproportion of the overall wing span. For example, it might have a spanof approximately 10 m (each side) compared to an overall wing span of 56m, to fit an airport gate envelope of 36 m wide.

According to a third aspect of the invention there is also provided anaircraft comprising the aircraft wing section assembly or aircraft wingassembly as described above.

The aircraft may have a high aspect ratio wing. For example, the span ofthe wing may be more than 40 m and maybe more than 50 m long. The aspectratio of the wing may be more than 12, maybe more than 14, and maybemore than 16.

According to a fourth aspect of the invention there is also provided amethod of operating an aircraft, the aircraft being as described above.

According to a fifth aspect of the invention there is also provided amethod of operating an aircraft, comprising the following stepsproviding a wing section with a structural spine extending in a spanwisedirection of the wing section, providing a support rod extending in achordwise direction of the wing section, through the structural spine,from a first end to a second end, actuating an actuation mechanism,thereby causing a first lever to pivot with respect to the support rod,thereby causing a first moveable wing control surface connected to thefirst lever to move, and a connection mechanism, connected to the firstlever and a second lever, to move, thereby causing the second lever topivot with respect to the support rod, thereby causing a second moveablewing control surface connected to the second lever to move.

It will of course be appreciated that features described in relation toone aspect of the present invention may be incorporated into otheraspects of the present invention. For example, the method of theinvention may incorporate any of the features described with referenceto the apparatus of the invention and vice versa.

DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample only with reference to the accompanying schematic drawings ofwhich:

FIG. 1 shows a plan view of a wing according to a first embodiment ofthe invention;

FIG. 2a shows a cross-sectional side view of a tip portion of the wingof FIG. 1, with leading and trailing edge cambering devices in a neutralconfiguration;

FIG. 2b shows a cross-sectional plan view of the tip portion of FIG. 2a, showing a movement mechanism for moving the leading and trailing edgecambering devices;

FIG. 3a shows a cross-sectional side view of the tip portion of the wingof FIG. 1, with leading and trailing edge cambering devices in anupwardly deflected configuration;

FIG. 3b shows a cross-sectional plan view of the tip portion of FIG. 3a, showing the movement mechanism for moving the leading and trailingedge cambering devices;

FIG. 4a shows a cross-sectional side view of the tip portion of the wingof FIG. 1, with leading and trailing edge cambering devices in adownwardly deflected configuration;

FIG. 4b shows a cross-sectional plan view of the tip portion of FIG. 4a, showing the movement mechanism for moving the leading and trailingedge cambering devices;

FIG. 5 shows cross-sectional plan view of a different movement mechanismthat could be used in a second embodiment;

FIG. 6 shows a cross-sectional plan view of the wing tip portion of FIG.1, showing a plurality of movement mechanisms, and an actuationmechanism;

FIG. 7a is a plan view showing a cable link mechanism of the actuationmechanism, in a disconnected configuration;

FIG. 7b is a plan view showing the cable link mechanism connected, inthe downwardly configuration;

FIG. 7c is a plan view showing the cable link mechanism connected, inthe upwardly configuration;

FIG. 8 shows a cross-sectional plan view of a wing tip portion in athird embodiment, showing a plurality of movement mechanisms, and anactuation mechanism; and

FIG. 9 shows a front view of an aircraft including an aircraft wing,suitable for being provided with the wing according to any of the aboveembodiments.

DETAILED DESCRIPTION

FIG. 1 shows a plan view of a wing 100 according to a first embodimentof the invention.

The wing 100 has a relatively large aspect ratio (span divided by meanchord). This aspect ratio is 16, with a span of 52 m. The wing comprisesa root portion 101, a main portion 102 and a tip portion 103. The tipportion 103 is a foldable wing tip, foldable in relation to the mainportion 102 at fold line 106. The wing has a leading edge 104 and atrailing edge 105.

The root portion 101 and main portion 102 are provided with a structuralwing box 107. In the tip portion 103, the main load-bearing structure isprovided by a structural spine, labelled as 108. The wing 100 also has awing skin 109, with the upper wing skin 109 a being seen in FIG. 1.There is also a lower wing skin 109 b on the underside of the wing.

Various moveable control surfaces 110 are provided on the wing 100.These are inboard flap 111, intermediate flap 112 and outboard flap 113in the root and main portions of the wing, and leading edge camberingdevice 114 and trailing edge cambering device 115 in the tip portion103.

FIG. 2a shows a cross-sectional side view of a tip portion 103 of thewing of FIG. 1, with leading 114 and trailing 115 edge cambering devicesin a neutral configuration, labelled as 114 a and 115 a respectively.

Here, it can be seen that the structural spine 108 is in the form of amonolithic box structure 180, with a top 181, bottom 182 and leading andtrailing sides 183, 184 respectively. The box 180 is 6 cm high (i.e. thelength of sides 183, 184) and is 12 cm wide (i.e. the length of top andbottom 181, 182). The box 180 is chord-wise located within the wing tip103 so as to achieve similar load magnitudes between the leading andtrailing sides, to reduce torsional stress on the box 180.

FIG. 2b shows a cross-sectional plan view of the tip portion 103 of FIG.2a , showing a mechanism 120 for moving and supporting the leading andtrailing edge cambering devices 114, 115.

Here, it can be seen that there are various holes in the sides 183, 184of the box 180. In particular, there is a hole in each of the sides 183,184 (the holes labelled 187 a and 187 b respectively) for a support rod121 which extends in the chordwise direction of the wing, through thestructural spine 108. Importantly, it does this at a central height ofthe monolithic box 180, as can be seen in FIG. 2a . It is at thiscentral height that the box 180 bears minimal load and hence, the holeshave minimal effect on the efficiency of the box structure 180. This isbecause the load is mainly being taken by the top 181 and bottom 182.

The support rod 121 comprises a leading stopper 122 and a trailingstopper 123. These are located outside of the leading and trailing sides183, 184 of the box 180 respectively and are attached to the sides 183,184 by nuts and bolts (not shown). (Alternatively, they could beattached with adhesive, rivets, co-curing, tension fitting using screwthread etc.) They ensure that the support rod 121 is fixed in place inrelation to the box 180 and allows the support rod 121 to transmit atension load and a compression load between the stoppers 122, 123.Hence, part of the hinge-moment load on the stoppers 122, 123 (from themovement mechanism 120, which will be described later) can betransferred through the support rod 121. In other words, the support rod121 allows hinge moments on the leading and trailing edge camberingdevices 114, 115 to counteract each other and provide an efficientstructure to deal with the loads experienced.

On each of the stoppers is a top lug 124 and a bottom lug 125 extendinghorizontally away from the box 180. These lugs 124, 125 mount a verticalpivot rod 126 extending between the lugs. The leading and trailing pivotrods 126 are used to mount two parts (leading part and trailing part) ofthe movement mechanism 120 that enable the leading and trailing edgecambering devices 114, 115 to be moved.

On either side of the holes 187 a and b (in the spanwise direction) aretwo further holes in each side 183, 184 of the box 180. The two holes inthe leading side are labelled 185 a and 185 b. The two holes in thetrailing side are labelled 186 a and 186 b. These holes allow steelcables 191 a and 191 a to extend through the box 180 to connect theleading and trailing parts of the movement mechanism 120, as will bedescribed later. (Alternatively, the cables could be made of any othersuitable material, such as carbon fibre.) This connection allows theleading and trailing edge cambering devices 114, 115 to be movedsimultaneously. Importantly, as before, the holes 185 a, 185 b, 186 a,186 b are at a central height of the monolithic box 180, as can be seenin FIG. 2a . When viewed head on, the shape of these holes may be in theform of an elongate slot with a longer width than height to accommodatefor the displacement of the cable in the spanwise direction due to thekinematics of the mechanism.

The trailing part of the movement mechanism 120 will now be described.The trailing part comprises a number of linked elements.

Firstly, a first crank lever 130 in the form of a short straight leveris pivotally mounted on the trailing pivot rod 126, so that it pivotsaround the vertical pivot rod 126. It is pivotally mounted at a centralpoint location 133 at pivot point 136. The crank lever 130 has a firstend 131, and second opposite end 132. Each end 131, 132 has acable-mounting point 134, 135. These cable-mounting points 134, 135attach to a moveable steel cable 161 of a cable mechanism 160, whichwill be described later. Movement of the cable 161 causes movement ofthe cable-mounting points 134, 135 and thus pivots the first crank lever130 about the pivot point 136.

A central location 143 of a second straight crank lever 140 is fixedlyattached to the first crank lever 130 at its central location 133, so asto form a perpendicular cross shape that pivots in relation to the pivotrod 126 at the pivot point 136. Hence, as the first crank lever 130pivots about 136 (because of cable 161 being moved), the second cranklever 140 also pivots about 136. The second crank lever 140 is longerthan the first crank lever 130. The second crank lever 140 has a firstend 141 and second opposite end 122. Each end 141, 142 has acable-mounting point 145, 146. These cable-mounting points 145, 146attach to cables 191 a and 191 b so as to connect the movement of thesecond crank lever 140 to the leading part of the movement mechanism, aswill be described later.

In addition, at an intermediate location 144 on the second crank lever140 there is a connecting link 150 pivotally mounted to the second cranklever 140. The intermediate location 144 is located apart from thecentral pivot point 143 of the lever 140 (or 136) but nearer to it inplan view, than either of the cable-mounting points 134, 135 on thefirst crank lever 130. This means that the movement of the cable 161that causes movement of cable-mounting points 134, 135 has a biggermoment arm in relation to the pivot point 136 of the crank levers 130,140 than the intermediate location 144. In fact, intermediate location144 is located approximately half the distance from the pivot point 136as the cable mounting points 134, 135. This means that the force (fromthe cable 161) needed at cable-mounting points 134, 135 to move thecranks 130, 140 is less than the force experienced by the intermediatelocation 144/connecting link 150. In addition, as the cable 161 loopsaround pulley 162 it exerts forces in opposing directions at the cablemounting points 134 and 135 such that the moment around pivot 136 isdoubled. This further increases the leverage of the cable 161 over theconnecting links 151 and 193. As the first 130 and second 140 cranklevers pivot, the intermediate location 144 moves towards and away fromthe trailing side 184 of the box 180.

The connecting link 150, as mentioned above, is pivotally connected tothe intermediate location 144 of the second crank lever 140. This is ata first end 151 of the connecting link. The second opposite end 152 ofthe connecting link (which extends towards the trailing edge camberingdevice 115) is pivotally mounted to a pivot bar 154 at pivot point 153.Hence, as the connecting link 150 is pulled into and pushed away fromthe trailing side 184, by the second crank lever 140, the pivot bar 154is also pulled into and pushed away from the trailing side 184.

The pivot bar 154 extends between two D-shaped cranks 155, 156. As canbe seen in FIG. 2a , an upper portion of each D-shaped crank (only crank155 seen) is pivotally mounted at pivot point 157 to the trailing edgeof upper wing skin 109 a. This pivot point 157 is above the pivot point153 of the pivot bar 154. Hence, when the pivot point is pushed towardsthe trailing edge cambering device 115, the D-cranks 155, 156 pivotupwards and vice versa. The trailing edge cambering device 115 ismounted to the D-cranks 155, 156 and so when they pivot at 157, thetrailing edge cambering device 115 also pivots. It is noted that on theupper and lower wing skins of the trailing edge cambering device 115, ata region adjacent the rest of the tip portion 103, are flexible sectionsof skin made out of CFRP (by winding fibres), denoted by label 158. Therest of the cambering device 115 comprises a fixed internal structure159. The flexible skins of the cambering devices 114, 115 that are onthe lower surface (i.e. furthest away from the pivots of the D-cranks)are disjoint from the lower surface skins of the wing tip portion 103.As the D-cranks pivot to place the cambering devices in the downwardconfiguration, the “excess′” flexible skin of the cambering devices 114,115 slides inside the wing cavity such that it is not exposed to theairflow. The flexible lower skin of each cambering device is attachedonly at the lower-inner corner of the D-crank, such that the remainingchordwise length of flexible skin is able to separate from the lowersurface of the D-crank in the upward configuration. In the downwardconfiguration, a chordwise length of the lower skin of the camberingdevice that is not attached to the D-crank will be drawn flush to thelower surface of the D-crank. Part of the D-crank is shaped to followthe arc of a circle around the D-crank pivot in order to maintain aconstant gap between the lower flexible skin of the cambering devices114, 115 and the skin of the wing tip portion 103 as the mechanism movesbetween the upward and downward configurations.

Going back to consider the cable mechanism 160 in more detail. Thiscable mechanism comprises a steel tensioned cable 161 looped around apulley 162 (although other materials could be used). The pulley 162 ismounted, using a pulley mount 163 to the trailing side 184 of the box180. The pulley 162 is mounted at a tip/outboard end of the tip portion103, as can be seen in FIGS. 6 and 8. At an opposite end of the tipportion 103 to the pulley (or in a main portion 102 of the wing) is acable actuator 164, which will be described later, in relation to FIGS.6 and 8. This cable actuator 164 moves the cable 161 back and forthbetween a first position and second position over the pulley.

In FIGS. 2a and 2b , the cable 161 is in an intermediate position,halfway between the two extreme positions. In this position, thecable-mounting points 134, 135 are in a position such that the firstcrank lever 130 is perpendicular to the trailing side 184 and the secondcrank lever 140 is parallel to the trailing side 184 of the box 180. Inthis position, the intermediate location 144 of the second crank lever140 is an intermediate distance spaced apart from the trailing side 184.Hence, the position of the connecting link 150 and pivot bar 154 causethe trailing edge cambering device 115 to be in a neutral configuration,pivoted neither upwards nor downwards.

As mentioned before, cables 191 a, 191 b extend from the second cranklever 140 through the holes 185 a, b, 186 a, b of the box 180 to theleading part of the movement mechanism 120. This leading part comprisesa crank bar 192, which is pivotally connected to the leading pivot rod126 at its central location, in a similar way to the second crank lever140. It is the same length as the second crank lever 140, and the cables191 a, 191 b are mounted to the ends of the crank bar 192, again in asimilar way to the second crank lever 140. This means that as the secondcrank lever 140 is pivoted clockwise, the tension on the cable 191 acauses the crank bar 192 to also pivot clockwise. When the second cranklever 140 is pivoted anti-clockwise, the tension on the cable 191 bcauses the crank bar 192 to also pivot anti-clockwise.

The crank bar 192 pivotally mounts a connecting link 193. This issimilar to how the second crank lever 140 mounts the connecting link 150at intermediate location 144.

Similarly, the connecting link 193 is attached through pivot bar 194 toD-shaped cranks 195, 196. These D-shaped cranks are connected to theleading edge cambering device 144 at pivot point 197 (above theconnection of the pivot bar 194 to the D-shaped cranks 195, 196). Hence,when the pivot bar 194 is pushed towards the leading edge camberingdevice 114, the D-cranks 195, 196 pivot upwards and vice versa. Theleading edge cambering device 114 is mounted to the D-cranks 195, 196and so when they pivot, the leading edge cambering device 114 alsopivots. It is noted that on the upper and lower wing skins of theleading edge cambering device 114, at a region adjacent the rest of thetip portion 103, are flexible sections of skin made out of CFRP (bywinding fibres), denoted by label 198. The rest of the cambering device114 comprises a fixed internal structure 199.

Importantly, the pivotal mounting of the connecting link 193 is on theopposite side of the support rod 121 to the intermediate location 144.This can be seen in FIG. 2b . This means that as the second crank lever140 is pivoted clockwise and the pivot bar 154 is pushed out towards thetrailing edge cambering device 115 (causing the trailing edge camberingdevice 115 to pivot upwards), the crank bar 192 is pivoted clockwise andthe pivot bar 197 is pushed out towards the leading edge camberingdevice 114 (also causing the leading edge cambering device 114 to pivotupwards). Hence, as the trailing edge cambering device 115 is pivotedupwards, so too is the leading edge cambering device 114. Similarly, asthe trailing edge cambering device 115 is pivoted downwards, so too isthe leading edge cambering device 114.

FIG. 3a shows a cross-sectional side view of the tip portion 103 of thewing of FIG. 1, with leading and trailing edge cambering devices in anupwardly deflected configuration, labelled as 114 b and 115 brespectively. FIG. 3b shows a cross-sectional plan view of the tipportion of FIG. 3 a.

Here, the cable 161 has been pulled by the cable actuator 164 so as torotate clockwise around the pulley 162. This causes the cable-mountingpoints 134, 135 to pivot the first and second crank levers 130, 140clockwise.

This causes two things: Firstly, the connecting link 150 pushes thepivot bar 154 outwards towards the trailing edge cambering device 115,causing it to pivot upwards to its upwardly deflected configuration 115b. Secondly, the cable 191 a pulls on crank bar 192 to pivot itclockwise, causing the pivot bar 194 to be pushed towards the leadingedge cambering device 114, thus causing the leading edge camberingdevice 114 to also be pivoted upwards to its upwardly deflectedconfiguration 114 b.

FIG. 4a shows a cross-sectional side view of the tip portion of the wingof FIG. 1, with leading and trailing edge cambering devices in adownwardly deflected configuration, labelled as 114 c and 115 crespectively. FIG. 4b shows a cross-sectional plan view of the tipportion of FIG. 4 a.

Here, the cable 161 has been pulled by the cable actuator 164 so as torotate anti-clockwise around the pulley 162. This causes thecable-mounting points 134, 135 to pivot the first and second cranklevers 130, 140 anti-clockwise.

This causes two things: Firstly, the connecting link 150 pulls the pivotbar 154 inwards away from the trailing edge cambering device 115,causing it to pivot downwards to its downwardly deflected configuration115 c. Secondly, the cable 191 b pulls on crank bar 192 to pivot itanti-clockwise, causing the pivot bar 194 to be pulled inwards away fromthe leading edge cambering device 114, thus causing the leading edgecambering device 114 to also be pivoted downwards to its downwardlydeflected configuration 114 b.

FIG. 5 shows cross-sectional plan view of a different movement mechanismthat could be used in a second embodiment. The movement mechanism andother elements are similar to that of the first embodiment, and the samereference numerals will be used. Only the differences will be describedbelow, using the same reference numerals, preceded by a 2, instead of a1.

Here, cable 191 b and associated holes 185 b and 186 b are not present.The crank bar 192 and second crank lever 140 are correspondinglyshortened as the relevant cable-mounting points (e.g. 146 on secondcrank lever 140) are not present. Cable 191 a is replaced by aconnection rod 291. This rod 291 transmits tension and compressionbetween the second crank lever 140 and crank bar 192.

Hence, when the cable 161 has been pulled by the cable actuator 164 soas to rotate clockwise around the pulley 162 and causes thecable-mounting points 134, 135 to pivot the first and second cranklevers 130, 140 clockwise, the trailing edge cambering device is pivotedupwards, as in FIGS. 3a and 3b . However, the connection rod 291 (ratherthan cable 191 a) pulls on the crank bar 192 to pivot it clockwise,causing the leading edge cambering device 114 to also be pivotedupwards.

When the cable 161 has been pulled by the cable actuator 164 so as torotate anti-clockwise around the pulley 162 and causes thecable-mounting points 134, 135 to pivot the first and second cranklevers 130, 140 anti-clockwise, the trailing edge cambering device ispivoted downwards, as in FIGS. 4a and 4b . However, the connection rod292 also pushes on the crank bar 192 to pivot it anti-clockwise, causingthe leading edge cambering device 114 to also be pivoted downwards.

FIG. 6 shows a cross-sectional plan view of the wing tip portion 103 ofFIG. 1, showing a plurality of movement mechanisms, corresponding tomovement mechanism 120, and an actuation mechanism, comprising the cableactuator 164.

In particular, there are three sets of the movement mechanisms andsupport rods etc. evenly distributed along the span length of the wingtip portion 103, outboard of the fold line 106. These are labelled as120 a, b and c. The movement mechanism 120 previously described,adjacent to the pulley 162 is movement mechanism 120 c in FIG. 6.Additional movement mechanisms etc. 120 a and b are inboard of theoutermost mechanism 120 c. They distribute the hinge-moment load alongthe span of the cambering devices 114, 115 and the rest of the wing tipportion 103.

Further, there are a number of additional pivotal D-shaped cranks(similar to 155 and 195) between the leading edge cambering device 114and the rest of the wing tip portion 103 and the trailing edge camberingdevice 115 and the rest of the wing tip portion 103. These are labelledas 127 a to d and 128 a to d, respectively. These serve as additionalhinges to support the structural connection between the wing tip portion103 and leading and trailing edge cambering devices 114 and 115, andmaintain the desired pivoting kinematics of the devices 114 and 115along their respective spanwise lengths. Hence, there are in total sevenconnection points between each of the leading edge 114 and trailing edge115 cambering devices and the rest of the wing tip portion 103.

As can be seen in FIG. 6, the cable 161 is looped around the pulley 162,which is located outboard of the outermost movement mechanism 120 c. Itis attached to all three movement mechanisms 120 a to c in the waydescribed above for movement mechanism 120/120 c. In particular, thecable 161 is attached at two cable-mounting points 134, 135 to the firstcrank lever 130 of each movement mechanism 120. Hence, as the cable 161is moved around the pulley, the causes both the cable-mounting points134, 135 on all movement mechanisms 120 to move simultaneously, and somove the cambering devices 114, 115 from all three movement mechanisms120 simultaneously.

The cable 161 is actuated by a cable actuator 164. This actuator 164moves the cable 161 between its two extreme positions, corresponding tothe extreme (upward and downward) positions of the cambering devices114, 115.

Importantly, in FIG. 6, the cable actuator 164 is inboard of the foldline 106 of the wing 100. Hence, there is a cable link mechanism 170 tolink the cable actuator 164 to the cable 161, as will now be described,with reference to FIG. 7a , which is a plan view showing a cable linkmechanism 170 in a disconnected configuration.

The cable actuator 164 is attached to a secondary steel cable 173 andmoves this cable 173 back and forth when actuating. The secondary cable173 is connected in two places to a first connection part 171 and causesthis first part 171 to change configuration.

The first part 171 comprises an upper fixed section 175 a whichpivotally mounts a lower part 174 a at a central region of the lowersection 174 a. The upper part 175 a is fixed to the main wing portion102. The lower section 174 a has the secondary cable 173 connected (at176 a, 177 a) to it at opposite ends such that movement of the cable 173causes the lower section 174 a to pivot with respect to the uppersection 175 a (and main wing portion 102). The lower section 174 a has astraight contact surface 178 a facing outboard (although the surfacecould be any suitable shape, e.g. curved).

This first part 171 abuts against a second part 172 so that the secondpart 172 also changes configuration when the first part 171 does. Thisabutment occurs at the fold line 106 so that there is no attachmentconnection across the fold line 106. The second part 172 is a mirrorimage of the first part 171 (at the fold line 106). The same referencenumerals will be used for the second part, but using a “b” instead of an“a”.

The second part upper section 175 b is fixedly connected to the wing tipportion 103. Hence, pivoting of the first lower section 174 a and thestraight surface 178 a causes pivoting of the corresponding straightsurface 178 b on the second part 172 and the pivoting of the second partlower section 174 b. The second part 172 is connected in two places (176b, 177 b) to the cable 161 and so this also causes the movement of thecable 161. Hence, movement of the cable 173 is reflected by the movementof cable 161.

FIG. 7b is a plan view showing the cable link mechanism in an engagedconfiguration, which corresponds to when the wing is fully unfolded.Parts 174 a and b are also partially rotated such that the mechanism isin the downwardly configuration.

Here, the cable actuator 164 has moved the secondary cable 173 causingit to pull on connection point 177 a (see arrows on FIG. 6). This hascaused the straight surface 178 a to pivot anti-clockwise. This alsocauses the straight surface 178 b to pivot anti-clockwise and so pull onconnection point 177 b. This causes the cable 161 to move anti-clockwisearound the pulley 162. Hence, this moves the leading edge 114 andtrailing edge 115 cambering devices to move to their downwardlyconfigurations 114 c, 115 c.

FIG. 7c is a plan view showing the cable link mechanism in the upwardlyconfiguration.

Here, the cable actuator 164 has moved the secondary cable 173 causingit to pull on connection point 176 a (reverse of arrows on FIG. 6). Thishas caused the straight surface 178 a to pivot clockwise. This alsocauses the straight surface 178 b to pivot clockwise and so pull onconnection point 176 b. This causes the cable 161 to move clockwisearound the pulley 162. Hence, this moves the leading edge 114 andtrailing edge 115 cambering devices to move to their upwardlyconfigurations 114 b, 115 b.

FIG. 8 shows a cross-sectional plan view of a wing tip portion 103 in athird embodiment, showing the same plurality of movement mechanisms 120,and a different actuation mechanism. This third embodiment is similar tothe arrangement of FIG. 6 and so only the differences will be describedbelow. The same reference numerals will be used where the elements arethe same. Where the elements are different, the same reference numeralswill be used, but suffixed by ‘.

In FIG. 8, the cable actuator 164’ is the same as cable actuator 164 butis located outboard of the fold line 106. It is connected directly tothe ends of cable 161′ (instead of secondary cable 173) and there is nocable link mechanism 170. Instead, the cable actuator 164′ moves thecable 161′ directly to move it between its extreme positions,corresponding to the extreme upwardly and downwardly configurations ofthe cambering devices 114, 115.

FIG. 9 shows a front view of an aircraft 10 including two aircraftwings, suitable for being the wing 100 according to any of the aboveembodiments.

Whilst the present invention has been described and illustrated withreference to particular embodiments, it will be appreciated by those ofordinary skill in the art that the invention lends itself to manydifferent variations not specifically illustrated herein. By way ofexample only, certain possible variations will now be described.

The pivot points of the D-cranks to the rest of the wing tip portion maybe above or below the pivot points of the pivot rods. In other words,the D-cranks could be mounted to the lower skin, rather than the upperskin.

Any suitable shape cranks, pivot rods, levers, bars etc. could be used.

The pulley cable could be replaced with an actuation rod that is movedback and forth between the extreme positions/configurations.

The flexible skin of the leading and/trailing edge could be made fromany suitable material. Alternatively, one or both of them may bereplaced with a hinge, such as a lug-pivot hinge.

The cable etc. or other actuation system may be located in the leadingedge, instead of the trailing edge.

The cable (or rod etc.) actuator may be located further inboard in thewing than shown in FIG. 6 or 8. However, it is advisable to locate it ina region of the wing that does not store fuel (i.e. a “dry area”).Alternatively, the actuator may be located further outboard than shownin FIG. 6 or 8.

A tapered wing and/or tapered wing box could be used, rather than theun-tapered planform shown in FIG. 6 or 8. In the case of a tapered wing,each mechanism could be adjusted to provide the desired leading edge andtrailing edge cambering device deflection along the span. The mechanismscould also be adjusted to vary the magnitude of leading edge andtrailing edge cambering device deflection along the span to achieve thedesired variation in lift distribution.

The different support rods of the mechanisms could be designed to take adifferent balance of load (between the support rod and the wing box)along the span of the wing tip.

One or more (including all) of the support rods may be pre-tensioned(e.g. through means of a screw). If pre-tensioned, they may act tosecure the structural spine with pins (extending from the stoppers intothe box sides, rather than with nuts and bolts). This would aidassembly.

The (relative vertical) positions of the support rods can be tuned toachieve a desired structural response in conjunction with the stiffnessof the structural spine.

The position at which each connecting link joins to the D-shaped crankscould vary to allow varying magnitudes of camber along the span of thewing tip portion. This could also provide the desired magnitudes ofleading edge and/or trailing edge deflection along the span of a taperedwing. This could also be used to vary the leverage within the mechanismsat each spanwise location in order to balance the forces and enable allmechanisms to be actuated with the same cable force.

Where in the foregoing description, integers or elements are mentionedwhich have known, obvious or foreseeable equivalents, then suchequivalents are herein incorporated as if individually set forth.Reference should be made to the claims for determining the true scope ofthe present invention, which should be construed so as to encompass anysuch equivalents. It will also be appreciated by the reader thatintegers or features of the invention that are described as preferable,advantageous, convenient or the like are optional and do not limit thescope of the independent claims. Moreover, it is to be understood thatsuch optional integers or features, whilst of possible benefit in someembodiments of the invention, may not be desirable, and may therefore beabsent, in other embodiments.

It should be noted that throughout this specification, “or” should beinterpreted as “and/or”.

1. An aircraft wing section assembly comprising: a structural spineextending in a spanwise direction of the wing section, a movementmechanism comprising: a support rod extending in a chordwise directionof the wing section, through the structural spine, from a first end to asecond end, a first lever, for connection to and for moving a firstmoveable control surface, pivotally mounted to the first end of thesupport rod, for pivotal movement with respect to the support rod, asecond lever, for connection to and for moving a second moveable controlsurface, pivotally mounted to the second end of the support rod, forpivotal movement with respect to the support rod, and a connectionmechanism for connecting the first and second levers such that pivotalmovement of the first lever with respect to the support rod causespivotal movement of the second lever with respect to the support rod,and an actuation mechanism for actuating pivotal movement of the firstlever with respect to the support rod such that, in use, when theactuation mechanism actuates pivotal movement of the first lever withrespect to the support rod, the second lever also pivotally moves withrespect to the support rod, thus causing movement of both the first andsecond moveable control surfaces.
 2. An aircraft wing section assemblyas claimed in claim 1, wherein the structural spine comprises amonolithic box structure.
 3. An aircraft wing section assembly asclaimed in claim 1, wherein the support rod comprises an elongatesection extending internally through the structural spine between thefirst and second ends, wherein the first end comprises a first endstopper located adjacent to a first external side of the structuralspine for preventing the first end from moving in a first directionthrough the first side, and wherein the second end comprises a secondend stopper located adjacent to a second, opposite external side of thestructural spine for preventing the second end from moving in a seconddirection, opposite to the first direction, through the second side. 4.An aircraft wing section assembly as claimed in claim 1, wherein theactuation mechanism comprises a cable connected to the first lever at afirst cable connection point, the cable being connected to a pullmechanism for pulling the cable such that the first cable connectionpoint moves.
 5. An aircraft wing section assembly as claimed in claim 4,wherein the actuation mechanism further comprises a pulley and whereinthe cable extends around the pulley.
 6. An aircraft wing sectionassembly as claimed in claim 5, wherein the cable is also connected tothe first lever at a second cable connection point.
 7. An aircraft wingsection assembly as claimed in claim 6, wherein the second cableconnection point is on an opposite side of the pulley to the first cableconnection point.
 8. An aircraft wing section assembly as claimed inclaim 4, wherein the actuation mechanism comprises a crank lever,mounted to the first lever such that it extends transverse to the firstlever and wherein the first cable connection point is located on a firstend of the crank lever, to a first transverse side of the first lever.9. An aircraft wing section assembly as claimed in claim 8, wherein thesecond cable connection point is located on a second opposite end of thecrank lever, to a second, opposite transverse side of the first lever.10. An aircraft wing section assembly as claimed in claim 1, wherein theconnection mechanism comprises at least one connector extending in achordwise direction of the wing section, through the structural spine.11. An aircraft wing section assembly as claimed in claim 10, whereinthe connection mechanism comprises a second connector extending in achordwise direction of the wing section, through the structural spine.12. An aircraft wing section assembly as claimed in claim 1, wherein thefirst lever is part of a first lever mechanism for connection to thefirst moveable control surface, and wherein the first lever mechanismalso comprises a connecting link pivotally mounted to the first lever ata connecting link connection point.
 13. An aircraft wing sectionassembly as claimed in claim 12, wherein the connecting link connectionpoint is closer to the point of pivotal mounting of the first lever tothe support rod than the location of the first cable connection point.14. An aircraft wing section assembly as claimed in claim 12, whereinthe first lever mechanism further comprises a D-shaped crank pivotallyconnected to the structural spine and connected to the connecting linksuch that movement of the connecting link causes the D-shaped crank topivot with respect to the structural spine.
 15. An aircraft wing sectionassembly as claimed in claim 1, wherein there are a plurality ofmovement mechanisms spaced apart along the structural spine.
 16. Anaircraft wing section assembly as claimed in claim 1, further comprisinga first moveable control surface connected to the first lever and asecond moveable control surface connected to the second lever, whereinone or both of the moveable control surfaces comprise a flexible skinadjacent to connection of the surface to the lever.
 17. An aircraft wingassembly including the aircraft wing section assembly of claim 1,wherein the aircraft wing section assembly is located at a tip portionof the aircraft wing assembly.
 18. An aircraft wing assembly as claimedin claim 17, comprising a foldable wing tip portion and wherein theaircraft wing section assembly is located in the foldable wing tipportion, such that it is located outboard of the fold.
 19. An aircraftwing assembly as claimed in claim 18, wherein the pull mechanism islocated outboard of the fold.
 20. An aircraft wing assembly as claimedin claim 18, wherein the pull mechanism is located inboard of the fold,and wherein the pull mechanism includes a cable link transfer mechanismto transfer movement of a cable inboard of the fold into movement of thecable outboard of the fold.
 21. An aircraft comprising the aircraft wingsection assembly or aircraft wing assembly of claim
 1. 22. A method ofoperating an aircraft, the aircraft being as claimed in claim
 21. 23. Amethod of operating an aircraft, comprising the following steps:providing a wing section with a structural spine extending in a spanwisedirection of the wing section, providing a support rod extending in achordwise direction of the wing section, through the structural spine,from a first end to a second end, actuating an actuation mechanism,thereby causing a first lever to pivot with respect to the support rod,thereby causing: a first moveable wing control surface connected to thefirst lever to move, and a connection mechanism, connected to the firstlever and a second lever, to move, thereby causing: the second lever topivot with respect to the support rod, thereby causing a second moveablewing control surface connected to the second lever to move.